Process for the preparation of monocyclic ketones and their alkyl derivatives having more than nine ring members



Patented Feb. 19, 1929.

uNiTEo STATES LEOPOLD RUZICKA, 0F GENEVA,

SWITZERLAND, ASSIGNOR TO M. NAEF & 00., OF

GENEVA, SWITZERLAND, A COMPANY OF SWITZERLAND.

PROCESS FOR THE PREPARATION OF MONOCYCLIC KETONES AND THEIR ALKYL DE- BIVATIVES HAVING MORE THAN NINE RING MEMBERS.

No Drawing. Application filed November 19, 1926', Serial No. 149,540, and in Switzerland December In the prior application Serial.No. 36,049

filed June 9, 1925, there is described a process of preparing monocychc ketones having more than nine ring members, which comprises heating a normal straight chain aliphatic members and of their alkyl derivatives, from the dicarboxylic acids having more than ten carbon atoms in a normal chain or from their alkyl derivatives, the metals and the compounds of metals belonging to the rare earths may advantageously be employed.

According to the present invent-ion erbium, which belongs to the said metals, or its compounds such as for instance erbium oxide are employed either alone or mixed with another metal or metal compound belonging to the said group.

It is also advantageous to use a mixture of several metals of the third or fourth group of the periodic system, these mixtures being obtained artificially or otherwise.

Mixtures of the above mentioned dicarboxylic acids or their alkyl derivatives, prepared from the pure acids, or as they are I 3 methyl tetradecane 1.14 dicarboxylic acid is heated up to above 300 to 500 degrees obtained in certain technical methods or from natural products, give, according to the present invention, mixtures of the ketones, or their alkyl derivatives, which, in

this form, can also be employed in practice.

preparation of other technically important compounds.

Example 1.

The erbium salt of 3-methyl-tetradecane- 1.14-dicarboxylic acid is heated, preferably 1n a vacuum, up to 300 to 500 degrees centigrade and the distillate obtained therefrom is worked up by fractional distillation. The fractions distilling at from 100 to 150 C. at a pressure of 0.5 mm. are then treated with semicarbazide or other reagents usually employed for isolating the ketones.

The formation of the 3-methyl-cyclopentadecanone can be represented, by the following equation:

.centigrade and towards the end of the reaction preferably in a vacuum with erbium hydroxide in a quantity which does not suf fice for completely converting the acid into the normal salt. The product obtained is treated according to the method described in Example 1.

- Example 3.

A mixture of the erbium and cerium salts of 4- methyl tetradecane- 1.14- dicarboxylic acid is heated and worked up as described in Example 1. The -methyl-cyelopentadecanone obtained boilsat about 125 C. (at

0.3 mm.), gives a semicarbazone melting at about 160 C. and has a smell like that of natural musk and can therefore be used as perfume and for preparing other interesting technical compounds.

Ewa/mple 1}.

l-irnethyl-tetradecane-1.1 l-dicarboxylic acid is heated at about 300 to 500 C. and towards the end of the reaction preferably in a vacuum, with erbium oxide. The product obtained is worked up as described in Example 3,

Ewample 5.

The erbium salt of tetradecane-LM-dicarboxylic acid is heated and worked up as described in Example 1. The cyclo-pentadecanone is obtained which distills at about 120 C. (at 0.5mm.) and melts at 03 0.

Example 6'.

Tetradecane-lld-dicarboxylic acid is heated at about 300 to 500 6., towards the end of the reaction preferably in vacuum, with erbium hydroxide. The distillate resulting therefrom is worked up as described in Example 5.

v Ewample 7'.

The anhydride of tetradecane-Lld-dicarboxylic acid is heated to about 300 to 500 (3. towards the end of the reaction preferably in a vacuum with erbium hydroxide and worked up as described in Example 5.

Ewa-mple 8.

An erbium salt of tetradecane-lld-dicarboxylic acid is prepared by partially neutralizing this acid with sodium hydroxide and precipitating with erbium chloride. The resulting erbium salt is decomposed by heating and worked up as described in Example 5.

Example .9

an intermediate for preparing other intcresting technical compounds; by oxidizing the cyclononadecanone with chromic acid heptaclecane-LlZ-dicarboxylic acid is formed.

Emample 10..

A mixture of cyclopentadecanone and cyclohexadecanone is obtained by working up according to the method described in Example 1 a mixture of erbium and cerium salts of tetradecane-l.ll-dicarboxylic and pentadecane-1.15-dicarboxylic acids.

I claim:

1. A process for the preparation of monocyclic ketones having more than nine ring members comprising heatii'ig rare earth metal salts of polymethylene dicarboxylic acids having more than ten carbon atoms in a normal chain, the carboxylic acid groups being linked to the end carbons thereof.

2. A process for the preparation of monocyclio ketones having more than nine ring members comprising heating erbium salts of polymethylene dicarboxylic acids, 'having more than ten carbon atoms in a normal chain, the carboxylic acid groups being linked to the end carbons thereof.

3. A process for the preparation of monocyclic ketones having more than nine ring members comprising heating a mixture of polymethylene dicarboxylic acid salts of rare earth metals having more than ten carbon atoms inga normal chain, the carboxylic acid groups being linked to the end carbons thereof.

4. A process for the preparation of monocyclic ketones having more than nine ring members comprising heating a mixture of erbium salts and cerium salts of polymethylene dicarboxylic acids having more than ten carbon atoms in a normal chain, the carboxylic acid groups being linked to the end carbons thereof.

In testimony whereof I afiix my signature.

LEOPOLD RUZICKA. 

